>>>Hi,
>>>
>>>Do you know what would cause the error?
>>>

>>>cannot redefine THIS.
>>>

>>>
>>>TIA
>>
>>THIS is a keyword, refers to an object like a window or a control. Just enter the following in the command window to see the error occur:
>>
>>

>>this = 5
>>

>>
>>Anything like that in your code, perhaps where you wanted to reference a property of the object THIS refers to?
>
>Hi Jos (or anyone else who could help with this),
>
>I was thinking of what you wrote (above) some days ago. In the command window I can duplicate this error (as you correctly wrote). Could you think of an example, of how I would duplicate this error in a VFP form at run time?
>
>TIA

Are there any places in the code where you're using macro substitution?